Attachment for weaving high density fabrics



M. MAYER, JR., ETAL ATTACHMENT, FOR WEAVING HIGH DENSITYFABRICS FiledApril 24. 1951 Aug. 25, 1953 3 Sheets-Sheet l lNVENiORS M.MAYER JR.G.J.KYAME ZJfl-MW ATTORNEY Aug. 25, 1953 M. MAYER, JR, ETAL ATTACHMENTFOR WEAVING HIGH DENSITY FABRICS Filed April 24, 1951 V s Sheets-Sheet zm r R mJ WR E Y A M ATTORNEY Aug. 25," 1953 M. MAYER; JR.. EI'AL12,649,864

ATTACHMENT FOR WEAVING HIGH DENSITY FABRICS J5 Sheets-Shegt 3 Find April24, 1951 JQVENTORS M.MAYER JR. G.J.KYA ME {my W ATTORNEY Patented Aug.25, 1953 ATTACHMENT FOR WEAVIN G HIGH DENSITY FABRICS Mayer Mayer, Jr.,and George J. Kyame, New Orleans, La., assignors to the United States ofAmerica as represented by the Secretary of Agriculture Application April24, 1951, Serial No. 222,726

(Granted under Title 35, U. S. Code (1952),

sec. 266) 4 Claims.

The invention herein described may be manufactured and used by or forthe Government of the United States of America for governmental purposesthroughout the world without the payment to us of any royalty thereon.

This invention relates to weaving. More particularly it provides a newmethod of weaving which produces fabrics having a smoother look and feelthan those produced by the processes of weaving heretofore known. Thenew method is capable of producing denser fabrics than can be producedby the processes of weaving heretofore employed. In addition, theinvention provides an apparatus which is capable of mechan cally weavingby the new method, and which is suitable for mounting upon any loom.

It is old in the loom art to produce special effects in cloth byapplying variable tensions to the warp yarns during weaving. Forexample, a cover may be produced on the cloth if the warp yarns formingone of the shed layers are given a greater tension than the remainingyarns as the lay beats up. The means heretofore used for obtaining theadded tension in the warp yarns are varied. Frequently the tension isobtained, to a certain extent, by raising the whip roll and the sandroll or breast beam, but these methods are not always satisfactory orpractical. For over twenty years it has been known that cover could beobtained by attaching to a loom an apparatus embodying a bar extendingtransversely across the warp strands, close to the shed harnesses, whichbar deflected from their normal approach to the shed harnesses the warpstrands, at the time they are pulled into shed layers by the harnesses.However, while by such means, for certain weave patterns, all of thewarp strands are, in the consecutive deflecting motions of the bar,deflected by the .bar'; different additional tension is applied to partof the warp strands to which additional tension is applied. For example,since the shed harnesses are arranged in banks and some banks are closerto the deflecting bar the warp strands running through the closest banksof the shed harnesses receive the greatest additional tension for agiven distance of deflection.

In the above and other means heretofore used for applying variabletension to the warp yarns during the weaving, the resultant fabricsoccasionally had a greater density than would have been obtained in theabsence of the application of the additional tension. However, themajority of the fabrics so produced were characterized by their lack ofuniformity which was the purpose for which the tension was varied. Inaddition,

the increase in fabric density was slight because the occasionalvariation in the tension resulted only in an occasional closer packingof the threads into the fell.

We have found that if during the process of weaving. the war strands aredivided into two groups each of which contain half of the total numberof strands as well as half of the strands passing through each twoconsecutive dents in the reed, and an additional tension isintermittently applied substantially uniformly upon all of the strandsin one group and then upon all of the strands in the other group, withadditional tension being applied at the moment of extreme beatup and atleast partially released between beats, and with the additional tensionbeing applied so that the warp strands approach the shed harnesseswithout substantial deviation from the normal warp line; the fabricsproduced are unobviously and advantageously different from fabrics ofthe same composition produced by the same loom without such asynchronized uniform application ofintermittent additional tension.

In contrast to the fabrics produced by the application of variabletensions during weaving, as heretofore practiced; the fabrics producedby the synchronized uniform application of intermittent additionaltension (i. e. produced as described in the preceding paragraph) have asmoother look and feel than do fabrics of the same composition woven bythe methods heretofore known.

In addition, the density of fabrics woven with a synchronized uniformapplication of intermittent additional tension is not solely dependentupon the mechanical limitations of the weaving equipment (as is the casein the methods of weaving heretofore employed), but is governedsubstantially completely by the physical characteristics of the yarn andcloth construction. Particularly when the maximum application ofadditional tension is synchronized to occur at the instant of extremebeatup; fabrics of abnormally high density can be produced. Such fabricswithout chemical treatment or coatings of any kind, are highly resistantto penetration by liquids or gases.

Among the objects of the present invention is the provision of anapparatus which can be attached to any loom, and when so attached, is

' capable of accomplishing the synchronized uniintermittent additionalart from the following description, illustrations, and examples ofembodiments of the invention.

Fig. 1 is an oblique view showing the components of the attachment andtheir location relative to each other and to the loom.

Figures 2a, 2b and 2c are general schematic views of the attachment inthe neutral position, and in two successive beatup positions.

Fig. 3 is a schematic view showing how the stroke of the warp tensioningmember can be reduced.

Fig. 4 is a plan view showing another means for actuating the warptensioning member.

In the preferred embodiment, Fig. l, a push bar I, preferably one havingrounded top and bottom edges, separates warp l6 into two layers, 2 and3, respectively. Each of the layers contains, hal of the total number ofwarp strands and half of the strands passing through any two consecutivedents in the reed. A loading member such, as loading bar 4, which is asmooth flat plate having a centrally located aperture, which ispreferably one which closely fits the push bar and restricts itsvertical motion, yet, permits, free passage of said push bartherethrough, is fitted on push bar I. The overall length, of plate 4 ispreferably such that it extends. as far above and below the push bar asis necessary to prevent linking members, such as I2, from contacting thewarp, i. e. layers 2 or 3. A slotted member, such as slotted bar .isfittedaround push bar I. Member 5 is a smooth flat plate which isslotted to receive push bar I, The overall length, of; the slot is atleast twice the totalvertical; distance traversed by the push bar plusthe; vertical dimension of the bar. The lower ends of said, members 4,and 5 terminate in adjustable connecting members, such as threadedconnecting rods If} which screw into one end of turnbuckles II, whilethe upper ends terminate in connecting members, such aschain connectinlinks; I2 Flexible members, such as chains I3supportedfrom idlersprockets Mwhich are rotatably attached to superstructure I5, areconnected tov links I2, thereby positively linking members 4 and5 toeachother. Attached to the lower ends, of turnbuckles II areconnectingrods I! which, in turn, are pivotally attached to one end ofactuating members, suchaslevers 8 and 9. The other endsv of; said.levers are pivotally attached to supports such as I8which are fitted toa supportmount such,as. I9. Cams Band '1' are rigidly mounted on theloom camshaft 2a and make contact with cam follower. rolls 24 on levers8 and 9;, to, transmitflpowerfrom said camshaft to said levers. Spacedcompensator bars 22-are clamped in clamps 23 supported by brackets 2-4.Mounted on clamps 23 are push bar guides 25 which limit the lateralmovement of push'bar I.

The loom is preferably powered by a single motor in the conventionalmanner, and in such an embodiment, camshaft 20, shuttle harnesses 3fiand lay, sword 34 move synchronously and the relative time ofoccurrenceof their various functional motions is. adjustable-in theconventionalmanner. In. a particularly preferred embodiment' of thepresent invention the harnesses are adjusted to form a closed shedat'the-moment, of extreme beatup of lay sword 34 and cams Band I arepositioned so that push bar I applies the maximumadditional tensionto-one shed layer at the same moment, and-applies such tension to theother. shed layerat the-instant the reed is in the extreme beatupposition on the next stroke of the lay sword.

In placing the attachment on a loom, a particularly suitable arrangementis one which will permit loading push bar I (via load members 4) to beat, or as near as possible to, the so-called quarter points, i, e. onequarter the distance from each end of said bar.

As shown in Fig. 2a, warp I6 is threaded through the loom in theconventional manner: from the warp beam 25 over whip roll 28, throughdrop wires 29, harnesses 3i), and reed iii to the fell 32- of the wovenfabric 33. The presence of the attachment on the loom does not in anyway interfere with the threading up operation since it is so designedthat those parts which would interfere can be readily dismantled andreassembled after the warp is in place. Thus, with the warp in place,compensator bars 22 are clamped in position, one over and one under thewarp, and loading members 4 and 5 are brought up through the warp inline with chains I3, and connected thereto through. links I2. Warp I6 isthen separated into two sheets to form shed layers 2 and 3 in theimmediate vicinity of the aforementioned members. 4. and 5. Push bar. Iisinserted between. said shed layers and through members 4 and 5. Guides25v are then installed.

It isessential that one half. of the warp strands passing through anytwo adjacent dents of the reed be put in the same layer of war strandspassing above or below push bar I. All ofv the strands passing through agiven, dent. may be in the same layer, thus, thegroups in alternatedents of reed 3I will all be in the same shed layer and willsubsequently be on the same side of the push bar. A particularlypreferred: arrangement for the weaving of an oxfoldv or plain fabricisto have half of the strands passing through each, dent in the reed inthe same layer above or, below push bar I.

Cams 5 and I are preferably set out of phase with each other, andareadjusted so that push bar I reaches its extreme position, eitherupward or downward, when loom lay sword 34 is at its extreme forwardorbeatup position. Although the camsshown arecircular and rotateeccentrically, they neednot be so limited. Other cam shapes can be usedprovided they impart to said push bar one upward and-one downward strokewith each revolution of. loom camshaft 2B:

In Fig. 2a, the cams 6, I, and; levers, 8, 9, are shown in the neutralposition, in which case, push bar, I preferably exerts no pressure-oneither; shed layer 2: or 3; Lay sword 34' is in. its rearmost. positionand harnesses 30. have formed a shed 35 through which shuttle 3B istraveling to insert weft thread.3:l. As the loomoperates, lay sword 34advances causing reed:.3'I= to push weft 3'! toward fell 32 of fabric33. Meanwhile, cams 6 are pushing levers 8 downward causing push bar Ito exert pressure on shed layer 3 thereby placing the warp strands insaid shedlayer under extreme-tension.

At this timeshed layer 2 is preferably completely relaxed as-showninFig. 2b; As laysword 34reaches-itsforwardmost position, reed 31 beatsweft- 31 into fabric 33. slackened warp strands in shed layer 2= over orunderthe previouslypicked weftthread. As-the loom operation-continues,lay sword 34 retracts,- cams I push down-onlevers 9 which, through thedepending action ofloading members 5- and chains I3, return push bar Ito its neutral position. Harnesses 30 form' a reversedshed' 35 andshuttle 36 returns therethrough-to insert. another pick (Weft 31).

As lever 9 continues downward it preferably Weft 37'- thus forces thecauses push bar I to leave shed layer 3 and produce tension in shedlayer 2 as shown in Fig. 2c. The tightening of said shed layer draws thepreviously mentioned overriding or underriding weft thread into theplane of the fabric, while the new weft 31 forces warp strands from shed3 over orunder the pick just described. Lay sword 34 again retracts,lever 8 moves downward pulling push bar I to its neutral position,harnesses 30 form a normal shed, and the above described cycle is readyto repeat.

Compensator bars 22 are placed in close proximity to drop wires 29 andprevent any substantial movement of the warp out of the plane of thenormal warp line. Another important function of said compensator bars isto reducethe amount of vertical movement of push bar I required todevelop a given amount of tension in the warp shed layers. Thus. whilenot always necessary, it is desirable to have a second pair of suchcompensators on the opposite side of the push bar; this arrangement isshown in Fig. 3.

The amount of stroke of push bar I required for weaving a high densityfabric is dependent on the physical characteristics of the yarn used andon-the fabric construction. Turnbuckles II allow the regulation of saidstroke by controlling the amount of slack inchain linkage I3, thuspermitting the utilization of the total throw of camsB and I, or anyfractional part thereof. Springs 21 take up the slack in chains I3thereby maintaining the vertical alignment of loading members 4 and 5and preventing warp damage which would otherwise occur if loa-d members4 and 5 are free to slip around.

The invention is not limited to the particular apparatus describedabove. For example, load members 4 and associated cams, levers, etc. maybe positioned so as to apply load to push bar I at its extremities or'any other intermediate points without deviating from the spirit of theinvention. The same may be said for slotted member 5. A furthervariation would consist in making such arrangements as to cause slottedmember 5 to function outside the confines of warp I6, in which case saidload member would be omitted and chain I3 would be extended to joincorresponding connecting rod I0.

Another modification of the invention shown in Fig. 4. In thisarrangement cranks 39, fixed to the ends of jackshaft 40 are driven fromloom camshaft through suitable driving means such as a gear train, chainand sprocket drive, etc. Crankpins 4 I, adj ustably mounted on cranksinload members 4. The vertical component of the rotary motion ofcrankpins M is transmitted by connecting rods 42 to load members 4 andhence to push bar I. Guides 43, similar to guides 25 in the preferredembodiment, restrict push bar I to vertical motion only.

Tests have proven that our invention utilizes to the fullest extent thecompressibility of the yarn. For example, in the case of the firstfabric listed in Table I below. attempts were made to put in more than72 picks per inch with the attachment providing synchronized uniformapplication of intermittent additional tension, i. e., to put in 76 and78 picks. But in each case, pick counts made on the fabrics afterweaving revealed that they contained, as recorded, not more than '72picks per inch. This indicates that the limit of compressibility of theyarn was reached at '72 picks per inch. Without said attachment on the100m it was found that with gears for the production of more than 56picks per inch, the operation resulted in an abnormal number of endbreaks, thus in impractical operation. I

Data so obtained for typical fabric construe tions are given in thefollowing table; the yarns used were cotton yarns and were woven into anOxford pattern. In the weavings conducted in accordance with the processoflthe invention the two groups containing half the total warp strandsalso contained half of the warp strands passing through each dent in thereed, the maximum additional tension was applied and the harnessesformed a closed shed, at the instant of extreme beatup.

The high density fabrics woven by the process of our invention areextremely resistant to penetration by liquids or gases as may be seen inTable II, which gives data for the permeabilities of the above fabricshaving the maximum density weavable with and without the use of our 39,actuate connecting rods 42 which terminate invention.

Table II 'lh d Fabric tea 00mm Weight A1r Water P are are Invention WarpFilling yd. 1 Y No. used State Threads per in M1 124 50 9. 20 0184 9. 051, 14 124 72 10. 10 0171 32. 82 15. 9 12s 56 9. 37 0171 9. 1, 845 130 1010. 20 0164 28. 07 108 124 53 9. 00 0181 11. 4a 249 as 10. 34 0173 42.35 4. 2 12s as 9. 05 0162 10.47 1, 005 67 10. 24 0101 30. 28 103 122 53.5 9. 03 0175 10.80 265 122 70. a 10. 47 0168 5s. 50 0. 14 124 63 s. 800104 s. 45 1, 391 122 71 10. 34 0150 32. 47 s. 5

1 Time required for 300 cc. of air under constant pressure to passthrough an orifice covered with the fabric.

1 Volume of water leaking through an 8 x 8 inch fabric sample subjectedto the h drostatlc ressure of a water column of constant height for 6minutes. y p

A lain weave cotton fabric" composed of warp yarn of 36 72" and weftyarnof 18 72 was woven with 64- picks per inch in accordance with theprocessor the invention in the same manner as the above fabrics. Thefabric was subjected to the ASTM drop penetration test (the amount ofleakage, in 3 hours, through a fabric mounted on a 45 angle under aconstant stream of water from a shower head 8- ft. above the fabric)leakages of 8 cos. and 0 cc. were observed in tests of the untreatedfabric. Under the ASTM Suter hydrostatic head test, a head of 74.7 cm.was required-- tocause the first three drops to form on the oppositeside of the fabric.

The above fabric was mildew proofed in the conventional manner (causingits hydrostatic head test to increase to 76.5 cm.) and was exposed fortwo:- months to the semi-tropical weather in the vicinity of. NewOrleans, La. When the exposed fabric was again: subjected to the Suterhydrostatic head test, a head of 912.3 cm. was required to. cause thefist three drops to appear. The drop penetration test resulted in nopenetration. The impermeability properties of the" fabric hadmarkedlyimprovedupon weathering.

Having thus described our invention,,we c1aim-:

L In a loom having a warp beam, whip roll, drop wires, shuttleharnesses, shuttle lay sword and reed provided with dents, and a loomcamo shaft for operating movable parts, the apparatus comprising: ahorizontal push bar slidably mounted so that it is free to move in avertical direction, but not in a horizontal direction, and positionedbehind the drop wires so that it divides the Warp strands into twogroups each containing half of the total number of strands and half ofthe strands passing through each consecutive two dents in the reed; twoelongated fiat loading bars centrally pierced to receive and hold said'push bar, so that the push bar is: free to: move horizontally but notvertically with respect to the loadingv bars, positioned with theirwidth parallel to the warpstrands andextending above and below saidstrands further than saido loading bars move; a chain passing from eachof said load bars over an idler sprocket mounted on a loomsuperstructure to an elongated slotted flat bar positioned with itswidth paralleling the fiber strands and slottedtoaccommodate the travelof the push bar; cam actuated levers pivotally' attached to the saidloading and slotted bars through adjustable rigid connecting memhas andmounted below the loom cam shaft; cams rig-idly attached to the 10cmcamshaftpositioned to lower one of said levers the-same distance theother is allowedto rise; and horizontal guide bars rigidly mounted aboveand below the warp strands both of the aforesaid groups and mountedbetween the said push bar and the drop: wires so that all of the warpstrands are held substantially in the planeo'fthe normal warp line:-

2. In a loom having the standard loomparts comprising whipro'll, shuttleharnesses, lay sword and ree'd' providedwithdents, the apparatus whichcomprises: a vertically movable horizontal push bar dividing the warpstrands into two groups each containing half of the total number ofstrands and half off the strands passing through every two consecutivedents in the reed; a cam driven. push bar actuating. mechanism arrangedto raise and: lower the push bar sothat the warp strands passing aboveand below the. push! bar arerespectively deflected asthe reed reacheseach extreme: beatup position; and two horizontal bars rigidly mountedtransversely above and: below thewarp strands and positioned between thepush bar and the-drop'wiressothat the deflection imparted to thewarpstrands doesnot deflect the strands from the plane of the normal warpline as they pass forward along the-loom.

3a The apparatus ofcl'aimZ with the eamzdriven push ba-r' actuatingmechanism synchronized with the loom functions so that the pushbarreaches its maximum vertical travel and the harnesses position the shedlayers substantially in parallel at the instant of extreme b'eatup.

4-.. The. apparatusof claim=2 in which two horizontal barsrigidlymounted: transversely above and below the warp strands are positionedbetween the push bar andthe whip roll in addition to-thetwo-horizontalbars positioned-between the push bar and drop: wiresr MAYER MAYER) JR.GEORGE J.

References Cited inthefile of this patent- UNITED STATES PATENTS NumberName Date 76333628 Petersen i June 28', 1904 1,294,809 Johnstone Feb.18-,, 1-9-l9 1349;1'2-3' Benson Mar. 4, 1930 1,874,320 Liparif et alAug. 30-, 1932 2,556,055 Bahan June 5; 1951

